Occurrence and Classification of Proximal Endoleaks Studied for the Nellix EVAS Device

November 15, 2017—Leo H. van den Ham, MD, et al published findings from a study that aimed to analyze and categorize proximal endoleaks in a cohort of patients treated with endovascular aneurysm sealing (EVAS). The investigators noted that proximal type I endoleaks are associated with abdominal aortic aneurysm (AAA) growth and rupture and necessitate repair. The Nellix EVAS system (Endologix) is a unique approach to AAA repair, in which the appearance and treatment of endoleaks are also different. The findings are available online in European Journal of Vascular and Endovascular Surgery (EJVES).

The investigators explained that the study included patients presenting with proximal endoleaks who were treated between February 2013 to December 2015 in 15 experienced EVAS centers. CT scans were analyzed by a core laboratory. A consensus meeting was organized to discuss and qualify each case for selection, technical aspects, and possible causes of the endoleak. Endoleaks were classified using a novel classification system for EVAS.

As reported in EJVES, 1,851 patients were treated using EVAS and followed for a median of 494 ± 283 days. Among these, 58 (3.1%) patients developed a proximal endoleak (1.5% early and 1.7% late); 84% of the patients were treated outside the original instructions for use and 96% outside the current, refined, instructions for use. Most likely causes of endoleaks included low stent positioning (44.6%), hostile anatomy (16.1%), and a combination of both (33.9%). Treatment by embolization or proximal extension was performed in 47% of cases, with a technical success rate of 97%.

The study concluded that the overall incidence of proximal endoleak after EVAS is 3.1% after a mean follow-up period of 16 months, with 1.5% occurring within 30 days. The occurrence of endoleaks was related to patient selection and stent positioning. Early detection and classification is crucial to avoid the potential of sac rupture, advised the investigators in EJVES.